Laser energy can be put to a variety of beneficial uses, which are wavelength specific. That is, to accomplish one goal or to perform one type of medical procedure, a laser system providing an output at a first wavelength is required. To accomplish another goal or to perform another type of medical procedure, a laser system providing an output at a second wavelength is required.
One such application of laser systems arises in the medical context. For instance, in some surgical procedures, an Nd:YAG laser is used at an output wavelength of 1064 nm to achieve surgical or therapeutic results. Also, such a laser system can be frequency-doubled to provide a 532 nm wavelength output laser energy to accomplish other surgical or therapeutic results.
For example, the 532 nm light is strongly absorbed by hemoglobin in blood making it very effective in cutting and vaporizing vascular tissue. The 1064 nm light is not strongly absorbed in most tissue and penetrates deeply into tissue. With sufficient power at 1064 nm (approximately 20 to 80 Watts) this causes sufficient heating of tissue to coagulate blood, and hence the 1064 nm laser is effective in performing coagulation to reduce or stop bleeding during a surgical procedure. These properties of laser-tissue interaction make a combination 532 nm laser and a 1064 nm laser very useful for surgical applications.